Ce kit d'enceinte est composé de:

Lisez l'article rédactionnel sur projets-haut-parleurs.fr

Vota 4

The most common questions we are asked about our new products and in email inquiries start with the telling words, “Couldn’t you …?” Usually these questions are wondering about changing the shape from one piece to two pieces, using a reflex tube instead of a slit or vice versa, and whether the loudspeaker can be used for a home theater. This time, though, it was different – the caller wanted to use the Vota 3 with a pedestal, but not as a sub-sat set with an active module as we first suggested. Instead, he wanted to use it with a passive bass, possibly in the FT 11 department. It could work, we said, but a crossover would need to be developed, which meant extra work. Not that we shy away from work, but when you are making more for yourself, the building suggestion really should be realistic. So it couldn’t be a Vota Sub 16 or FT 11 on the bottom. Instead, because it looks much better and is not much more expensive, 2 AXT 08s, 2 AXT 05s and 1 NeoCD 3.0. We didn’t mention that we had been meaning to invent this combination for a long time, and had just been waiting for a reason to get started on it. We didn’t even have to think long about the name – in keeping with tradition, we called it the Vota 4﻿.

There was not much calculating to do for the cabinet; we had run the numbers for the AXT 08 several times already, and the best results showed 40 liters for each bass. Now, loudspeaker building is not an intolerant undertaking – every bass has some room for variation. That was a deciding factor when our gaze landed on an empty pair of boxes that was once known as the Axis 220 Neo. “Throw it out!” my wife had been saying for some time, but I remembered the story of the local farmer who, when asked about his old milking stool, said, “Aw, it’s broken!” When his friend said, “So why don’tcha throw it out?” of course, he replied, “Well, it ain’t THAT broken!” So we breathed new life into the beautiful wooden boxes by cutting out the fronts, gluing in some extra innards, and saving ourselves at least 2 hours of work and 60 euros in material costs. The two basses on each side now had to get by with around 70 liters, but all three of us decided we could live with that. Seven liters were shared by two AXT 05s, with a NeoCD 3.0 between them. In other words, we were able to elegantly answer the question, “Couldn’t you just put new speakers in my old cabinet?” in the affirmative﻿.

The mid-range tweeter’s back wall and floor were glued on using four stilts, once we had found the right position for the front boards during our test run and marked the front boards with a pencil. The previously oiled edges of the box needed to be sanded so that the joint glue could solidly hold the body and the front together. Two tension belts provided a little bit of pressure, since the existing black MDF boards were unfortunately not as straight as some of the simulations in various DIY forums. After two hours of drying time, though, they were lying flat as a pancake on the rest of the cabinet. All that was left was to sand the edges flat. But what was it we were saying about avoiding work? Anyway, here is the SketchUp drawing so you can reproduce it, along with the resulting building plan for the front and side﻿.

From the photo studio, it was time to go to the measurement room, where the chassis elements and insulation materials were installed in the boxes so the crossover could be developed. It wasn’t a long trip, since the two rooms share a wall. Instead of a new development, we went back to the existing crossover used in the Vota 3 for the mid-range tweeter unit. If necessary, the big sister could share the living room side with it, in case anyone decided to use them for a home theater. (In order to avoid another “Couldn’t you …”: yes, the Vota 1 is also ideal as a rear speaker.) Our work here was almost done – we replaced the mid-range coil, left out the series resistor in the tweeter, and made its capacitor a little bigger. Of course, we also had to add a high-pass filter using two parallel capacitors, and reduce the volume of the AXT 05 with a resistor. The two basses shared a coil and a capacitor, so our final measurements gave us wonderful separations at 250 and 3100 Hz. With a volume of at least 92 dB/ 2.83 V, an impedance correction for tube models was essential, too﻿.

As required, we have documented the final measurements here, with the usual diagrams﻿.

Frequency responce

Impedance

Distortion for 90 dB

Frequency 0/ 30/ 60°

Step responce

Waterfall

Before the Vota 4 made its way to the listening room for a listening test, we installed the crossovers, insulation, terminals and chassis elements. This was easily done through the bass cutouts, and it also took care of the question “Couldn’t you just put the innards into the box before you glue on the last board?” Of the seven bags of Sonofil™﻿ that come with it, six of them go behind the basses and one disappears into the mid-range chamber. The drawing shows where they go in the box. There is even a little insulation left over at the end, but that is fine﻿n.

Once all the construction work was finished, there came a moment when the question “Couldn’t you just publish a construction report without a sound description?” could be called rhetorical at best. So we headed to the listening studio, hooked up the Votas to an old Fisher receiver, and thought about what we should listen to first. It actually wasn’t such a hard decision, since according to our survey, the point of the Vota series was to project high-quality rock music into the room. As long as we were talking vintage, we might as well get a black disc spinning at an even speed on the record player. “Brothers in Arms” happened to be at the top of the pile, and the rain beating on the window went very nicely with the storm at the beginning of the title piece. But the realism of the scene by no means overshadowed Knopfler’s voice, guitar and precise drumbeats. Jethro Tull’s “Locomotive Breath” set our legs, head and arms bouncing – why didn’t we have boxes like this in the old days when we could still jump around the room to the music? Today our condition would have been better described by Helene Fischer – Atemlos (Breathless).

“Couldn’t you listen to classical, jazz or chart hits on the Vota 4?” would be the next question. And the answer would be an unconditional “yes.” Our youngest child is not picky when it comes to toys – it can have fun with anything. Even if it’s missing the last little something that would make it a Blues Class, the Vota 4 is a good addition to any living room where people want to listen to music﻿.

No one needs to ask the question, “Couldn’t you combine the Vota 3 and 1 to make an outstanding home theater?” but if they did, the follow-up question would surely be, “Couldn’t you add the Audible Sub 12 as an air mixer?” I already know Patrick Even’s answer: “They just don’t look right together! You should wait until the Vota 12 or 15 Sub has been introduced.”﻿

It’s nice to know that, despite our 150 or so building suggestions, there are still so many questions left to ask. That makes it easier for us to come up with more ideas. But if some day, we are asked a final question – “Couldn’t you get this magazine off the internet already?” – we would need to come up with an appropriate answer right away. Fortunately, we don’t think it will happen in our lifetime﻿.